Apparatus for raising a multi-element telescopic prop or the like



Aug. 28, 1962 R. voGEL ETAL 3,051,431

APPARATUS FOR RAISING A MULTI-ELEMENT Filed April 17, 1959 TELESCOPIC PROP OR THE LIKE 4 Sheets-Sheet 1 FIG. I

FIG. 2

Aug. 28, 1962 R. VOGEL ET AL 3,051,431

APPARATUS FOR RAISING A MULTI-ELEMENT TELESCOPIC PROP OR THE LIKE Filed April 17, 1959 4 Sheets-Sheet 2 {A FIG.3 1 $5 4 Ill/11111111111 INVENTORS E0004; V0551 BY A4422 flozrae Aug. 28, 1962 R. VOGEL ETAL APPARATUS FOR RAISING A MULTI-ELEMENT TELESCOPIC PROP OR THE LIKE 4 Sheets-Sheet 3 Filed April 17, 1959 INVENTORfi' 0000 664 BY Mez Has/6e Aug. 28, 1962 R. VOGEL ET AL 3,051,431

APPARATUS FOR RAISING A. MULTI-ELEMENT TELESCOPIC PROP OR THE LIKE 4 Sheets-Shet 4 Filed April 1'7, 1959 ATTORNEYS United States Patent 3,051,431 APPARATUS FOR RAISING A MULTI-ELEMENT TELESCOPIC PROP OR THE LIKE Rudolf Vogel, 0berhausen-terkrade, and Karl Hoefer,

Essen-=Frintrop, Germany, assignors to Gutehofinungshiitte Sterkrade Aktiengesellschaft, Oberhausen-Sterkrade, Germany Filed Apr. 17, 1959, er. No. $07,240 Claims priority, application Germany Apr. 23, 1958 12 Claims. (Cl. 248-354) The present invention relates to an apparatus for setting and clamping telescopic props or supports.

Adjustable iron props, formed of a plurality of telescopic parts, are used to support the roof in a mine. When the prop has been adjusted to its proper height, the inner and outer telescopic parts thereof are clamped together with a friction fit by a lock.

If an erected prop or support must carry the mine roof from the moment of its erection, the inner prop section must be forced or set against the roof before it is clamped against the outer prop section.

It is an object of the present invention to provide means aifording the utilization of a highly novel hydraulic device which is removable from the prop for clamping the prop parts together with a frictional fit therebetween.

In order to achieve a setting pressure and a lock tension which is as close to equal as possible for all the props in a mine, it has heretofore been proposed to use a removable hydraulic setting device, for the setting and clamping of the mine props, which imparts an adjustable initial stress to the prop and, upon attainment of this initial stress, releases a piston which forces a clamping wedge into the lock. With the use of such a removable setting and clamping device, the props can be set substantially uniformly and the miners physical efiort is greatly reduced. However, the miner must continually supervise the progress of the work and he must manually control it.

In fact, when the separate operating pistons for setting the prop and for tighening the lock have successively advanced to their projected positions, the setting device cannot be removed from the prop until release members have been manually operated so as to remove the pressure from the compression cylinders of the setting device and return the operating pistons to their retracted positions. Manual operation of the release members or device presents considerable difiiculties to the miner since he cannot precisely ascertain when the setting and clamping process has been completed, i.e. when the wedge has been pressed into the lock sufiiciently for the desired lock tension to be produced.

The same condition prevails when an excess pressure valve is installed in the pressure Zone to limit the lock tension, because the excess pressure valve is located between the storage tank or reservoir for the pressurized medium and the pressure cylinder so that the operation or reaction of the valve is not externally visible. Consequently, the miner can operate the release device only in accordance with the position of the wedge.

To avoid taking the setting device oif the lock prematurely with a consequent insufiicient lock tension, the miner will wait before he operates the release device until he is quite sure that the prop has the desired lock tension. Such a delayed operation of the release mechanism results in a considerable loss of time in the setting of the props, so that it becomes uneconomical to use hydraulic setting and clamping devices.

It is another object to provide means eifectuating the elimination of the disadvantages of prior art setting devices.

It is another object of the present invention to provide means facilitating the setting and clamping of mine props or the like by means of a hydraulic lifting mechanism in such a manner that time loss is completely eliminated and supervision of the process by the miner is obviated.

It is a further object of the present invention to provide means ensuring that all props are set with the same look tension.

These and other objects of the invention will become further apparent from the following detailed description, reference being made to the accompanying drawings showing a preferred embodiment of the invention.

In the drawings which illustrate the best mode presently contemplated for carrying out the invention:

FIG. 1 is a View, in side elevation, of a telescopic mine prop or the like, with applied lifting apparatus, pursuant to the present invention, for setting, clamping and fixing the prop;

FIG. 2 is a top plan view of the apparatus illustrated in FIG. 1, and with section taken along lines 2-2 of FIG. 1;

FIG. 3 is a more or less diagrammatic and schematic illustration of the mechanism in condition for setting, clamping and fixing the mine prop;

FIG. 4 is a view similar to FIG. 3 with the mechanism in the release condition thereof; and

FIG. 5 is an enlarged perspective view of the working head.

Briefly described, the present invention proposes a method and apparatus for setting and clamping telescopic props for mines or the like wherein following an automatically controlled operating sequence for the individual procedures, such as setting, clamping and specially locking the prop, the hydraulic prop lifting device is automatically returned to its starting condition.

With this automatic control of all operations, a fully automatic setting, clamping, and a subsequent fixing of the mine prop can be achieved with the lifting or prop raising mechanism. The miner merely applies the raising mechanism to the lock and all necessary operations occur in succession. Since the pressure is automatically removed from the lifting device after the setting and clamping operations and the device is restored to its initial operating or starting condition, the miner can no longer intervene in the setting and clamping processes at his own discretion, nor is it necessary for him to watch the setting and clamping processes. The reversal of the operating pistons can now occur in the lifting mechanism at the exact instant that the desired lock tension is achieved, so that, pursuant to the present invention, the setting and clamping of the mine props occurs in a minimum of time, and this was not possible in the prior art due to the delayed manual operation of the release device. At the same time, the automatic interruption of the setting and clamping process ensures that all props are set with the same lock tension.

Referring now to FIGS. 1 and 2 of the drawings in detail, there is shown a mine prop or support 1A constituted by an outer prop member 1 and an inner prop member 2 telescopically slida-ble therein. A lock 3 is utilized to frictionally clamp the two prop members or elements together. The prop is set directly behind a track 4 which runs along the mine face or wall 5, and supports the mine roof (not illustrated) by means of a cap 6 immediately below the roof, the prop extending from the mine floor 5A to the roof cap. In order to effect the automatic setting, clamping and the subsequent locking of the prop in its clamping condition, provision is made for a lifting mechanism 7. In order that the lifting mechanism can be readily handled without physical exertion by the miner it is subdivided into a working head 8, removably secured on the prop 1A, and a central unit 9 which can readily be moved along the floor 5A. The head and the drive are interconnected by a flexible conduit 10. As hereinafter described in detail, the operating head 8 essentially contains the operating pistons for setting, clamping and fixing the prop, as well as a canting device for engagement of the inner prop member 2 during setting.

All the other components of the lifting mechanism 7, such as a drive motor, a pressurized-medium pump, a storage tank for the pressurized medium, an automatic control device, valves, pressure converting or amplifying means, etc. are disposed within the central unit 9. The pressurized-medium pump is driven by a pneumatic motor which is supplied with compressed air through a compressed lair conduit 11 which extends from the longwall conduit 12 of the mine.

FIG. 3 is a more or less diagrammatic illustration of the lifting or raising mechanism 7 in condition for setting the prop 1A and for clamping and fixing the lock 3, for example in the case of a mine prop where the clamping of the inner prop member 2 against the outer prop member 1 occurs by two torque clamping members embracing the inner prop member. These clamping members are mutually clamped, in opposite directions, about the ion gitudinal axis of the prop, and they are provided with arms between which the removable hydraulic lifting mechanism 7 can be applied. The arms of the clamping members are forced apart by the lifting mechanism to produce the required lock tension. In order to retain the clamped condition of the clamping members after the lifting mechanism is removed from the prop, the lock 3 is provided with a fixing wedge. This wedge is moved into its locking position by the lifting mechanism simultaneously with the tightening of the lock.

The portion of FIG. 3 above line 13 represents the central unit 9 and the portion below the line represents the operating head 8. Conduit 10 which interconnects the central unit and the operating head is illustrated in section along the line 13.

In the central unit 9, compressed air from the longwall conduit 12 is supplied to a pneumatic motor 16 through a compressed air valve 14 interposed between conduit 15 andconduit 12. Motor 16 drives a high-pressure pump 17. Pressurized fluid is pumped by pump 17 from a storage tank or reservoir 18 through conduit 19 extending between the pump and the tank. The tank 13 is formed of a soft flexible material, preferably being constituted by a rubber bag, so as to facilitate pressure compensation during the emptying or filling of the tank. As the compressed air valve 14 is opened, pump 17 starts to operate and forces the pressurized fluid from tank 18 through conduit 19 into conduit 20 and into conduit 21 which branches from conduit 20. Fluid from conduit 21 enters an annular groove 22 defined in a piston valve 23, the fluid flowing from the groove through conduit 24 into a transformer or pressure converting amplifier 25, in which the pressure of the fluid is increased in accordance with the ratio of the different piston surfaces in the transformer.

From the transformer, the pressurized fluid flows through conduit 26 into annular groove 27 defined in the piston valve 23. From groove 27 the fluid flows through conduit 28 into the operating head 8. It will be noted that the fluid flow path in FIG. 3 is designated by a broken line representation of the various conduits through which the fluid flows.

The operating head 8 is provided with the three pressurized-medium piston cylinders 29, 30 and 31 provided with pistons 32, 33 and 34, respectively. Cylinder 29 serves to set the prop 1A, cylinder 30 serves to tighten the lock 3, and cylinder 3-1 fixes the lock by driving in a fixing wedge. In order to effect the automatic return of the operating pistons 32, 33 and 34 to their initial or starting position after the setting, clamping and fixing of the prop, their respective cylinders are designed for double admission of the pressurized fluid against opposite surfaces of the pistons. In the operating head 8, pressurized fluid is first admitted into cylinder 29 through conduit 28 to act upon the lower surface 32A of piston 32 to raise the latter. During the advance or rise of piston 32, the inner prop member 2 is raised or lifted over a canting lever (not illustrated) and forced against the roof.

A suction or one way valve 84 is provided which serves as a suction valve for the pressure connecting transformer 25 so that the piston of the transformer 25 can return upward to its starting position after operation of work pistons 32, 33 and 34. After pistons 32, 33 and '34 have attained their extended positions, the piston valve 23 is actuated and the transformer 25 becomes pressureless above the pressure piston, as shown in FIG. 4. The spring 52 functions to press the piston of the transformer 25 upwardly which causes an underpressure in the pressure space beneath the piston. The valve 84 accordingly opens and the pressure space is fed from the reservoir 18.

Upon the piston of the pressure transformers 25 being actuated by pressure fluid from above during successive working steps, the pressure increases to thereby close the valve 84. When the valve 84 is closed, there is no fluid connection between the reservoir 18 and the pressure space of the transformer 25.

When the adjusted setting load is reached, an excess pressure one way valve 35, between cylinders 29 and 30, opens upon additional increase in the pressure, so that the pressurized fluid is admitted into both the cylinders 33 and 31 and reacts against the lower surfaces 33A and 34A of their respective pistons 33 and 34 so as to concomittantly raise or advance said pistons. Piston 33 clamps the lock and piston 34 forces in or inserts the fixing wedge. Since a much greater force is required to tighten the lock than to insert the fixing wedge, piston 34 may have a much smaller diameter than the clamping piston 33. However, all the pistons are shown as being the same size in the drawings for purposes of illustration. During the advance of the double-acting pistons 32, 33 and 34, the fluid can flow back to the reservoir 18 from the opposite pressure free sides 32B, 33B and 34B of the pistons. Said fluid return path can be traced, as shown in full line, through. conduit 37 to the annular groove 38 of the piston valve 23 and from the latter through conduits 33, 40 and 19 to the reservoir 18. The compressed air barrier or valve 14 is connected to conduit 41 and the latter is connected to line 21 by a valve 43.

During the setting, clamping and fixing operations, valve 43 is closed so that the blocking conduit 41 is free of pressure and the valve 14 remains open to admit pressure from conduit 12 into conduit 15. A normally closed valve 36 is inserted between conduit 21) and the end face of the piston valve 23. Upon attainment of a predetermined pressure required for proper lock tension, the valve 36 is opened and the piston valve 23 is displaced longitudinally upwardly from its position shown in FIG. 3 to its position shown in FIG. 4.

Referring now to FIG. 4 in detail, the lifting mechanism is illustrated with the piston valve 23 reversed. Upon reversal thereof, the various pressure carrying conduits are interchanged with the various pressure free conduits, so that pressurized fluid now reacts against the upper faces 32B, 33B and 34B of pistons 32, 33 and 34, respectively, immediately after discontinuance of the setting and clamping process. Tracing the flow of the pressurized fluid in broken line, it will be noted that pressurized fluid is now admitted to the annular groove 38 of the piston cylinder 23 through conduits 5d and 51.

As a result, pressurized fluid flows through conduit 37 to the upper piston surfaces 32B, 33B and 34B so that the respective pistons are retracted to their initial or starting positions. The former pressure carrying conduit 28 is now connected to annular groove 42 of the piston valve 23 and is free of pressure, it being noted that fluid returns from the lower piston surfaces 32A, 33A and 34A through conduit 28, and one way valve 35'. .The annular groove 42 is connected to reservoir 18 through conduits 40 and 19 for the return of the fluid to the reservoir 18. Annular groove 22 .also becomes pressure free concomittantly with groove 42 so that conduit 24 between groove 22 and pressure transformer 25 becomes pressure free. As a result, the transformer is returned to its raised or starting position by a compression spring 52 which was tensioned as a result of the lowering of the transformer upon admission of pressurized fluid thereto, as in FIG. 3.

When all three pistons 32, 33 and 34 have been completely returned to their retracted positions, the pressure increases again due to the continued operation of the high pressure pump 17 until a maximum predetermined pressure is attained.

Upon attainment thereof, sufiicient pressure is applied to the closed valve 43, through conduits 20 and 21 to open the latter whereupon pressurized fluid is introduced into conduit 41 so as to close valve 14 and discontinue the supply of compressed air from conduit 12 to motor 16. As a result, the pneumatic motor 16 and the pressure pump 17 immediately discontinue operation. The raising mechanism 7 can now be removed from the set prop 1A and be applied to the next prop which is to be set.

For completion of all operations, the piston valve 23 must be returned to its retracted or starting position, illustrated in FIG. 3, from its projected position shown in FIG. 4. This is readily accomplished from the operating head 8. The operating head is provided with a pull ring 44 which is connected to the piston valve 23, disposed within the central unit 9, by a Bowden cable 45. The pressure conduits 28 and 37 and the Bowden cable 45 are all combined in the previously described cable which extends from the central unit 9 to the working head 8. Therefore, it will be understood that when the ring 44 is pulled from its full line to its broken line position, as illustrated in FIG. 4, the valve 23 is returned to the position thereof shown in FIG. 3.

Operati0ns.Frorn the foregoing, it will be apparent that all that need be done for setting and clamping a multi-element prop, pursuant to the present invention, is to apply the working head 8 of the hydraulic lifting device 7 to the prop, as shown in FIGS. 1 and 2, and pull the ring 44 from its full position shown in FIG. 4 to its broken line position shown in FIG. 4 so that the ring is in the full line position shown in FIG. 3 and the piston valve 23 is returned to its starting position shown in FIG. 3. After that, the various operations occur automatically in succession since, by operation of the pull ring 44, the conduit 41 is rendered free of pressure so that valve 14 is opened whereupon compressed air is applied to the pneumatic motor 16 which is rendered operative and, in turn, automatically starts the operation of the pressure pump 17. Through the pressure transformer 25, the operating pistons 32, 33 and 34 are successively operated by the pressurized fluid or medium and they set, clamp and fix the prop 1A. By operation of the adjustable valve 36 at attainment of a predetermined pressure, the piston valve 23 is automatically reversed, whereupon the operating pistons are returned to their retracted starting positions. The compressed air valve 14 is then operated by the pressurized fluid or medium so that it closes and stops the motor and pump. The next cycle can then take place.

The head 8 is placed on the prop 1 while it is supported via an abutment or yoke 85 against the end face of the prop. In order to take along the upper prop 2, there is provided a yoke or stirrup 86 which is pushed over the prop 2 and is disposed in vertical alignment and in contact with the piston 32. Upon movement of the piston 32, the upper prop 2 is also moved upwardly by the cocking or edging of the yoke 86. The prop 2 is moved until it abuts or bears against the ceiling of the mine. When the desired pressure has been obtained, the excess pressure valve 35 is actuated and the pistons 33 and 34 of the tensioning and arresting cylinders are subjected to the liquid pressure and are thus moved. The piston 33 acts in this procedure in a spreading sense onto two arms 87, 87 of the lock 3.

Due to the spreading of the arms 87, 87, two tensioning rings in the lock 3 are turned in opposite directions about the longitudinal axis of the prop so that the upper prop 2 is frictionally clamped in the lock. In order to maintain this tensioning condition in the lock there is provided an arresting wedge 38 which, during the tensioning procedure caused by the movement of the piston 34 via a lever 89, is pushed into the locking position. When the movements of the working pistons 32, 33 and 34 have been completed, then, due to the reversing cycle 23, an automatic return of the piston takes place into the starting position so that the head 8 can easily be taken off the lock 3 and be used for the setting and tensioning of the next prop. The tensioning condition is maintained by the arresting wedge 88 which is left on the prop.

Due to the automatic control of the various operations, the setting and clamping of the prop occurs in a minimum of time. The operating time depends only upon the volume delivered by the pump. All that the miner or operator needs to do is to apply the lightweight working head 8 to the prop lock 3, while the central unit 9 provided with the motor, pump, transformer and valves, rests on the mine floor. If the connecting conduits to the prop to be set are not long enough, the central unit can be easily dragged along the floor.

It will be understood that the present invention is not limited to the described illustrative embodiment. Other and further modifications may be made therein, within the scope of the present invention. For example, it is possible, pursuant to the present invention, to set and clamp props, by the described method, where the lock is tightened by driving in a clamping wedge. In this case the clamping piston simultaneously elfects the fixing of the prop, so that a special fixing piston is not needed.

Various changes and modifications may be made without departing from the spirit and scope of the present invention and it is intended that such obvious changes and modifications be embraced by the annexed claims.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent, is:

1. Apparatus for raising a multi-element telescopic prop including a first prop member, a second prop member telescopically slidable in said first prop member and a lock for frictionally clamping said first and second prop members in their extended telescoped condition, comprising first reversible pressure-responsive means operable in one direction for raising and applying a predetermined pressure to the prop, second reversible pressure-responsive means adapted to be connected to said. lock operable in one direction for clamping said prop members with respect to one another, third reversible pressure-responsive means operable in one direction for fixing said lock in clamped condition, pump means for providing a pressurized fluid for operating said first, second and third reversible means, pressure-responsive-pressure-transrnitting means interposed between said pump means and said first, second and third reversible means for applying pressure to said first, second and third reversible means, and pressure-responsive control means for controlling said pressure transmitting means so that after attainment of a predetermined pressure sufficient to operate said first, second and third reversible means in said one direction, operation of said pump means effects operation of said first, second and third reversible means in an opposite direction, respectively, thereof.

2. Apparatus as set forth in claim 1, further characterized in that said control means comprises .a piston valve having a cylinder connected by a conduit to the output of said pump means, and an adjustable excess pressure valve in said conduit for operating said piston valve after attainment of said predetermined pressure.

3. Apparatus as set forth in claim 1, further characterized in that said pressure transmitting means is connected to said first reversible means and the latter is connected to said second and third reversible means by an excess pressure valve which is adjusted to admit pressure to said second and third reversible means after operation of said first reversible means in said one direction thereof.

4. Apparatus as set forth in claim 1, further characterized in that said pressure transmitting means is connected to said first reversible means and the latter is connected to said second and third reversible means by an excess pressure valve which is adjusted to admit pressure to said second and third reversible means after operation of said first reversible means in said one direction thereof, said first, second and third reversible means each comprising a cylinder provided with a piston and having means for admitting pressurized fluid to opposite surfaces, respectively, of said piston.

5. Apparatus as set forth in claim 1, further characterized in that said pump means and said pressure-responsive-pressure transforming means are provided in a central unit adapted to be disposed on a supporting surface, and a working head, said first and second reversible means being provided in said working head, said working head being adapted to be mounted on said prop and being operatively connected to said central unit.

6. Apparatus as set forth in claim 1, further characterized in the provision of a pneumatic motor for said pump means, valve means for controlling the supply of compressed air to said motor, and means responsive to the pressure in said apparatus for closing said valve means upon setting and clamping of said prop.

7. Apparatus as set forth in claim 1, further characterized in the provision of resilient reservoir means for storage of a pressure medium, said reservoir means being operatively connected both to said pump means and said pressure transforming means.

8. A device for attachment to a telescopic prop including a first prop member, a second prop member telescopically slidable in said first prop member and a lock for frictionally clamping said first and second prop members with respect to one another in their extended relative telescopic arrangement, comprising a first relatively slidable fluid piston and cylinder combination connectible to one of said prop members for raising said prop member until it bears against a fixed element such as a ceiling with a predetermined force, a second relatively slidable fluid piston and cylinder combination connectible to the lock to move the lock into a clamped condition, fluid pressure means, and control means connected between said fluid pressure means and said first and second piston and cylinder combination and effective to direct pressurized fluid to one side of the piston of said first fluid piston and cylinder combination until a predetermined pressure is reached and to thereafter direct the fluid to the second of said fluid piston and cylinder combination to tighten said clamp after said prop members are in position bearing a load.

9. A device according to claim 8, wherein said control means includes a movable valve element, said valve element being displaceable between said actuated position in which it permits fluid pressures to be directed to said first fluid piston and cylinder combination and a deactivated position in which fluid pressure is withdrawn from said fluid piston and cylinder combination.

10. A device according to claim 8, wherein said fluid pressure means includes a fluid motor, a fluid pressure source for operating said motor, and said control means includes means for automatically disconnecting said fluid motor from said fluid supply means upon completion of an operating cycle.

11. A device according to claim 8, including third fluid piston and cylinder means, said lock including means for wedging' said lock in a clamped position, said third fluid piston and cylinder means being connected to said control means and being actuated upon setting up of the lock and being connectible to the wedge to wedge said lock in a clamping position.

12. A device according to claim 8, wherein said control means includes means movable upon completion of said clamping to disconnect said fluid pressure means from said first and second fluid and piston cylinder combination.

References Cited in the file of this patent UNITED STATES PATENTS 2,365,536 Fischer et al. Dec. 19, 1944 2,403,912 Doll July 16, 1946 2,573,993 Sedgwick Nov. 6, 1951 2,665,555 Martinsson Jan. 12, 1954 FOREIGN PATENTS 202,536 Austria Mar. 10, 1959 744,899 Great Britain Feb. 15, 1956 

